1 files changed, 25 insertions, 13 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index f4b60294a969..cf18d87da41e 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5507,12 +5507,12 @@ out:
 	return rc;
 }
 
-static int qeth_set_online(struct qeth_card *card)
+static int qeth_set_online(struct qeth_card *card,
+			   const struct qeth_discipline *disc)
 {
 	bool carrier_ok;
 	int rc;
 
-	mutex_lock(&card->discipline_mutex);
 	mutex_lock(&card->conf_mutex);
 	QETH_CARD_TEXT(card, 2, "setonlin");
 
@@ -5529,7 +5529,7 @@ static int qeth_set_online(struct qeth_card *card)
 		/* no need for locking / error handling at this early stage: */
 		qeth_set_real_num_tx_queues(card, qeth_tx_actual_queues(card));
 
-	rc = card->discipline->set_online(card, carrier_ok);
+	rc = disc->set_online(card, carrier_ok);
 	if (rc)
 		goto err_online;
 
@@ -5537,7 +5537,6 @@ static int qeth_set_online(struct qeth_card *card)
 	kobject_uevent(&card->gdev->dev.kobj, KOBJ_CHANGE);
 
 	mutex_unlock(&card->conf_mutex);
-	mutex_unlock(&card->discipline_mutex);
 	return 0;
 
 err_online:
@@ -5552,15 +5551,14 @@ err_hardsetup:
 	qdio_free(CARD_DDEV(card));
 
 	mutex_unlock(&card->conf_mutex);
-	mutex_unlock(&card->discipline_mutex);
 	return rc;
 }
 
-int qeth_set_offline(struct qeth_card *card, bool resetting)
+int qeth_set_offline(struct qeth_card *card, const struct qeth_discipline *disc,
+		     bool resetting)
 {
 	int rc, rc2, rc3;
 
-	mutex_lock(&card->discipline_mutex);
 	mutex_lock(&card->conf_mutex);
 	QETH_CARD_TEXT(card, 3, "setoffl");
 
@@ -5581,7 +5579,7 @@ int qeth_set_offline(struct qeth_card *card, bool resetting)
 
 	cancel_work_sync(&card->rx_mode_work);
 
-	card->discipline->set_offline(card);
+	disc->set_offline(card);
 
 	qeth_qdio_clear_card(card, 0);
 	qeth_drain_output_queues(card);
@@ -5602,16 +5600,19 @@ int qeth_set_offline(struct qeth_card *card, bool resetting)
 	kobject_uevent(&card->gdev->dev.kobj, KOBJ_CHANGE);
 
 	mutex_unlock(&card->conf_mutex);
-	mutex_unlock(&card->discipline_mutex);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qeth_set_offline);
 
 static int qeth_do_reset(void *data)
 {
+	const struct qeth_discipline *disc;
 	struct qeth_card *card = data;
 	int rc;
 
+	/* Lock-free, other users will block until we are done. */
+	disc = card->discipline;
+
 	QETH_CARD_TEXT(card, 2, "recover1");
 	if (!qeth_do_run_thread(card, QETH_RECOVER_THREAD))
 		return 0;
@@ -5619,8 +5620,8 @@ static int qeth_do_reset(void *data)
 	dev_warn(&card->gdev->dev,
 		 "A recovery process has been started for the device\n");
 
-	qeth_set_offline(card, true);
-	rc = qeth_set_online(card);
+	qeth_set_offline(card, disc, true);
+	rc = qeth_set_online(card, disc);
 	if (!rc) {
 		dev_info(&card->gdev->dev,
 			 "Device successfully recovered!\n");
@@ -6584,6 +6585,7 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev)
 		break;
 	default:
 		card->info.layer_enforced = true;
+		/* It's so early that we don't need the discipline_mutex yet. */
 		rc = qeth_core_load_discipline(card, enforced_disc);
 		if (rc)
 			goto err_load;
@@ -6616,10 +6618,12 @@ static void qeth_core_remove_device(struct ccwgroup_device *gdev)
 
 	QETH_CARD_TEXT(card, 2, "removedv");
 
+	mutex_lock(&card->discipline_mutex);
 	if (card->discipline) {
 		card->discipline->remove(gdev);
 		qeth_core_free_discipline(card);
 	}
+	mutex_unlock(&card->discipline_mutex);
 
 	qeth_free_qdio_queues(card);
 
@@ -6634,6 +6638,7 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev)
 	int rc = 0;
 	enum qeth_discipline_id def_discipline;
 
+	mutex_lock(&card->discipline_mutex);
 	if (!card->discipline) {
 		def_discipline = IS_IQD(card) ? QETH_DISCIPLINE_LAYER3 :
 						QETH_DISCIPLINE_LAYER2;
@@ -6647,16 +6652,23 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev)
 		}
 	}
 
-	rc = qeth_set_online(card);
+	rc = qeth_set_online(card, card->discipline);
+
 err:
+	mutex_unlock(&card->discipline_mutex);
 	return rc;
 }
 
 static int qeth_core_set_offline(struct ccwgroup_device *gdev)
 {
 	struct qeth_card *card = dev_get_drvdata(&gdev->dev);
+	int rc;
 
-	return qeth_set_offline(card, false);
+	mutex_lock(&card->discipline_mutex);
+	rc = qeth_set_offline(card, card->discipline, false);
+	mutex_unlock(&card->discipline_mutex);
+
+	return rc;
 }
 
 static void qeth_core_shutdown(struct ccwgroup_device *gdev)